Response to nivolumab in metastatic collecting duct carcinoma expressing PD-L1: A case report

The authors present a case report of collecting duct carcinoma (CDC) that responded to nivolumab, a programmed death 1 (PD-1) immune-checkpoint-inhibitor antibody, following the failure of systemic treatment with chemotherapy and targeted therapy. The patient underwent right radical nephrectomy and segmentectomy of the lung following chemotherapy. Fifteen months following the first surgery, segmentectomy and subsequent second-line chemotherapy were performed for recurrence in the lung. Targeted therapy with temsirolimus for recurrence of the lung and lymph node metastases was ultimately used for 30 months. However, the temsirolimus treatment failed to suppress the growth of metastatic lesions. Nivolumab resulted in complete response of the lung metastasis, and it stabilized the lymph node metastasis. PD-L1 was highly expressed in both primary tumor and the metastatic regions. Therapy with nivolumab is ongoing. These findings suggest that treatment with nivolumab may be considered for metastatic and treatment-failure CDC.